added acer runner (missing import)

baselines/acer/runner.py

@@ -0,0 +1,60 @@
+import numpy as np
+from baselines.common.runners import AbstractEnvRunner
+
+class Runner(AbstractEnvRunner):
+
+    def __init__(self, env, model, nsteps, nstack):
+        super().__init__(env=env, model=model, nsteps=nsteps)
+        self.nstack = nstack
+        nh, nw, nc = env.observation_space.shape
+        self.nc = nc  # nc = 1 for atari, but just in case
+        self.nact = env.action_space.n
+        nenv = self.nenv
+        self.nbatch = nenv * nsteps
+        self.batch_ob_shape = (nenv*(nsteps+1), nh, nw, nc*nstack)
+        self.obs = np.zeros((nenv, nh, nw, nc * nstack), dtype=np.uint8)
+        obs = env.reset()
+        self.update_obs(obs)
+
+    def update_obs(self, obs, dones=None):
+        #self.obs = obs
+        if dones is not None:
+            self.obs *= (1 - dones.astype(np.uint8))[:, None, None, None]
+        self.obs = np.roll(self.obs, shift=-self.nc, axis=3)
+        self.obs[:, :, :, -self.nc:] = obs[:, :, :, :]
+
+    def run(self):
+        enc_obs = np.split(self.obs, self.nstack, axis=3)  # so now list of obs steps
+        mb_obs, mb_actions, mb_mus, mb_dones, mb_rewards = [], [], [], [], []
+        for _ in range(self.nsteps):
+            actions, mus, states = self.model._step(self.obs, S=self.states, M=self.dones)
+            mb_obs.append(np.copy(self.obs))
+            mb_actions.append(actions)
+            mb_mus.append(mus)
+            mb_dones.append(self.dones)
+            obs, rewards, dones, _ = self.env.step(actions)
+            # states information for statefull models like LSTM
+            self.states = states
+            self.dones = dones
+            self.update_obs(obs, dones)
+            mb_rewards.append(rewards)
+            enc_obs.append(obs)
+        mb_obs.append(np.copy(self.obs))
+        mb_dones.append(self.dones)
+
+        enc_obs = np.asarray(enc_obs, dtype=np.uint8).swapaxes(1, 0)
+        mb_obs = np.asarray(mb_obs, dtype=np.uint8).swapaxes(1, 0)
+        mb_actions = np.asarray(mb_actions, dtype=np.int32).swapaxes(1, 0)
+        mb_rewards = np.asarray(mb_rewards, dtype=np.float32).swapaxes(1, 0)
+        mb_mus = np.asarray(mb_mus, dtype=np.float32).swapaxes(1, 0)
+
+        mb_dones = np.asarray(mb_dones, dtype=np.bool).swapaxes(1, 0)
+
+        mb_masks = mb_dones # Used for statefull models like LSTM's to mask state when done
+        mb_dones = mb_dones[:, 1:] # Used for calculating returns. The dones array is now aligned with rewards
+
+        # shapes are now [nenv, nsteps, []]
+        # When pulling from buffer, arrays will now be reshaped in place, preventing a deep copy.
+
+        return enc_obs, mb_obs, mb_actions, mb_rewards, mb_mus, mb_dones, mb_masks
+